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How to make sure Respirator is filtering properly

Posted: Wed Oct 26, 2022 3:18 am
by MrMan123
Hello!
I've been welding for a while and every time I need to use Fluxcore or Stick with heavy fumes, I wear my Miller LPR-100 Respirator.
It came to my attention recently that if I can "smell" the fumes through my respirator it might not be working. I use the basic LPR-100 SA00818 that Miller says, "provides 99% protection", which I know is probably a load of baloney, but I dont use the Nuisance Odor ones that have Charcoal or whatever applied to them since the odors of Stick and Fluxcore don't really bother me when I smell them.
Every time I put on my respirator I do both pressure tests, of blocking my intakes and breathing in and feeling it collapse, and then doing the same with the exhale valve and feeling it bulge but never leak anywhere (and when it does I readjust and do it again).
I should also add that after a couple days, the outside of my filters are brown from the fumes, but the insides are still pristine white, and I have no black boogies or anything to indicate fumes are getting through my respirator.

Am I worrying over nothing or should I actually get the OV Filters Miller offers? I just wanna make sure that I'm keeping my lungs safe and I was under the impression that welding fumes are like campfire smoke, in that it's a bunch of tiny particulates floating upwards with steam.
Any help or information is appreciated, because I couldn't actually find much when searching for this topic.

P.S. I've also welded a whole bunch of galvanized with fumes flying into my face and never once felt sick so I don't know if I got lucky or what if my respirator isn't working properly.

Re: How to make sure Respirator is filtering properly

Posted: Sun Oct 30, 2022 11:48 am
by Oscar
If the price difference isn't that much, go for the OV relief versions. Might as well. I've only used the 3M 2297 pancake filters that have carbon layers and they work really well so I'm not using anything different anytime soon.

Re: How to make sure Respirator is filtering properly

Posted: Mon Oct 31, 2022 3:00 am
by Arno
Smells don't only come from particles, so a plain filter will still let you smell some byproducts from the welding process as they are pure gaseous form or so small that they pass a filter.

As an example: even with a good (low micron) particlefilter you'd still smell rotting eggs as the gas they give off (hydrogen sufilde) is what you smell and not any particles, so it's not filtered out.

To reduce that you need to add active chemical filtering like activated carbon which binds many complex molecules and sub-micron particles that trigger your smell receptors in your nose, so it's much reduced.

As you mention that the mask does seal well when blocking in or outlets, Orscar's suggestion of using a filter with a carbon layer will probably take care of most of the smell.

Bye, Arno.